<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style type="text/css">
        body{
            padding: 0;
            margin: 0;
        }
        #content{
            margin:  0 auto;
            width: 600px;
            overflow: hidden;
            border: 1px solid grey;
        }
        #left{
            float:left; width:150px; background:#B0B0B0;
            padding-bottom:2000px;
            margin-bottom:-2000px;
        }
        #right{
            float:left; width:450px; background:#6CC;
            padding-bottom:2000px;
            margin-bottom:-2000px;
        }

    </style>
</head>
<body>
    <div id="content">
    <div id="left">我是left</div>
    <div id="right"> 我是Right<br/><br/>我要求和left和我一样高</div>
    </div>
<script>

</script>
</body>
</html>